by Bri Dandrea
Sensory processing disorder is a condition where the brain has difficulty recognizing, receiving, or responding to sensory stimuli. Deficits are commonly seen with the vestibular system, proprioceptive system, tactile system, or visual system, but may also be seen within the auditory, gustatory, or olfactory system as well. I will explain the first four systems a little later. Sensory processing disorder may present as a hyper-response (over-response) to stimuli or an under-response to sensory stimuli.
Over-responsiveness can also be described as ‘sensory defensive’. The child may have an over-reaction to touch, movement, sound, odor, or even taste. Anxiety is very common among children who are over-responding to sensory input. Typical behaviors seen from children who are sensory defensive include anxiety, distractibility, restlessness, anger, tantrums, aggression, fear, or emotional distress. Self-care activities, school activities (such as messy crafts, or playground activities), and social interactions may cause discomfort for the child.
Children who are under-responsive to sensory stimuli typically seem like they are unaware of touch, pain, movement, taste, smell, sights, or sounds. With this, one or more systems can be affected. The biggest worry of their lack of response is safety. For example a child may not respond to sights or sounds, which can be dangerous if the sounds are fire alarms or sirens.
Children with under-responsiveness typically seek sensory input or are slow to register. If the child seeks sensory input they might enjoy crashing into objects, jumping onto or off furniture, and may even chew or bite object’s. These are the kids that have a hard time sitting still. On the other hand, children who are slow to register to sensory input may seem clumsy, bumping into objects often. They also seem to fatigue quickly with activity.
The vestibular system is responsible for informing our brain about the motion of our body, head position, and spatial orientation. This helps us keep our balance, maintain posture, and stabilize our body. Children who have difficulty with processing vestibular input may be fearful of movement, balance activities, or activities where their feet leave the ground. Playgrounds are often a place of fear. This difficulty can also appear as an inability to sit still, incoordination with activity, and increased anxiety.
The Proprioceptive System
The proprioceptive system is responsible for informing our brain where our body is in space and where our body parts are in relation to each other. Receptors (or the alarm signals) for this system are in muscles, tenons, and joints. This system is needed for motor planning for movements of the arms, hands, legs, ect. It can tell us how much force to use during activity as well. Again much like difficulties with the vestibular system, children who have difficulty receiving proprioceptive information tend to be clumsy or awkward. They may break toys, or rip their paper while writing due to unawareness of the pressure they are using.
The Tactile System
The tactile system is in charge of registering light touch, deep touch, pain, and temperature. The system is important for fine motor skills needed to complete tasks like buttoning, snapping, braiding hair, holding a pencil, or even manipulating a spoon. Children will often have increased frustration when trying to complete fine motor tasks.
The Visual System
Visual perception is important for play and fine motor tasks. Typically this is defined as difficulty with depth perception, visual closure, or spatial orientation. Children likely have difficulty with tactile perception as well when visual perception is difficult. It can present in many different ways, and there are tests a therapist can administer to narrow down the area of deficits.
This is very general information about some of the sensory systems that are affected and in no way should be used to diagnose deficits. Sensory processing disorder can present itself in many different ways, and may look different in each child. If you have concerns or these descriptions sound like a familiar problem your child is having please reach out to a pediatric specialist.
Case-Smith, J.; O’Brian, J. (2015). Occupational therapy for children and adolescents. Evlsevier Mosby.